TY - JOUR T1 - Cytochrome P450 2S1 is Reduced by NADPH-Cytochrome P450 Reductase JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 944 LP - 946 DO - 10.1124/dmd.111.039321 VL - 39 IS - 6 AU - Yi Xiao AU - Raku Shinkyo AU - F. Peter Guengerich Y1 - 2011/06/01 UR - http://dmd.aspetjournals.org/content/39/6/944.abstract N2 - Cytochrome P450 (P450) 2S1 is one of the orphan P450s without a clear physiological function. Controversy has arisen as to whether it can interact with NADPH-P450 reductase and accept electrons. The reduction of 1,4-bis{[2-(dimethylamino-N-oxide)ethyl]amino}-5,8-dihydroxyanthracene-9,10-dione (AQ4N) by P450 2S1 was confirmed, and the NADPH consumption rates were measured aerobically and anaerobically in the absence and presence of the drug. The reduction kinetics of P450 2S1 were rapid, as measured by stopped-flow kinetics. These results confirm that P450 2S1 can be reduced by NADPH-P450 reductase and suggest normal mixed-function oxidase roles of P450 2S1 to be revealed. ER -